Guarantee real time processing of soft real-time operating system by instructing core to enter a waiting period prior to transferring a high priority task

Abstract

A method to guarantee real time processing of a soft real time operating system in a multicore platform by executing a thread while varying a core in which the thread is executed and apparatus are provided. The method includes assigning priority to a task thread, executing the task thread, determining a core in which the task thread is to be executed, and if the core is determined, transferring the task thread to the determined core.

What is claimed is: 
     
       1. A method to guarantee real time processing of a soft real time operating system in a multicore platform, the method comprising:
 assigning, by a first core, a highest priority to a first task thread, wherein the first task thread is a real time task thread configured to be executed periodically at each of a plurality of periods; 
 executing, by the first core, the first task thread during a first period of the plurality of periods; 
 determining, by the first core, a second core in which the first task thread is to be executed during a second period of the plurality of periods; 
 instructing, by the first core, the second core to enter a waiting period prior to transferring the first task thread thereto, wherein entering the waiting period includes spinning or a combination of spinning and sleeping by the second core until the second period occurs; 
 stopping execution, by the second core, of a second task thread executing on the second core in response to the first core instructing the second core to enter the waiting period and the second core subsequently entering the waiting period; 
 transferring the first task thread to the second core while the second core is in the waiting period; and 
 executing, by the second core, the first task thread when the second period occurs after the first task thread is transferred thereto. 
 
     
     
       2. The method according to  claim 1 , wherein executing the task thread includes executing the task thread when the second period occurs. 
     
     
       3. The method according to  claim 1 , wherein the determining includes determining which one of a plurality of cores in the multicore platform to assign as the second core according to a task thread arrangement scheme. 
     
     
       4. The method of  claim 1 , further comprising:
 first transferring codes and read only data associated with the task thread from the first core to the second core during execution thereof by the first core; and 
 second transferring read-write data associated with the task thread from the first core to the second core after execution thereof by the first core is complete. 
 
     
     
       5. A non-transitory computer-readable recording medium having stored therein a program that, when executed by a multicore processor, configures the multicore processor to:
 assign, by a first core, a highest priority to a first task thread, wherein the first task thread is a real time task thread configured to be executed periodically at each of a plurality of periods, 
 execute, by the first core, the first task thread during a first period of the plurality of periods 
 determine, by the first core, a second core in which the first task thread is to be executed during a second period of the plurality of periods, 
 instruct, by the first core, the second core to enter a waiting period prior to transferring the first task thread thereto, wherein entering the waiting period includes spinning or a combination of spinning and sleeping by the second core until the second period occurs, 
 stop execution, by the second core, of a second task thread executing on the second core in response to the first core instructing the second core to enter the waiting period, and the second core subsequently entering the waiting period, 
 transfer the first task thread to the second core while the second core is in the waiting period, and 
 execute, by the second core, the first task thread when the second period occurs after the first task thread is transferred thereto. 
 
     
     
       6. An apparatus to guarantee real time processing of a task thread in a soft real time operating system in a multicore platform, comprising:
 a first core and a second core, wherein 
 the first core is configured to,
 assign a highest priority to a first task thread according to a task thread arrangement scheme, wherein the first task thread is a real time task thread configured to be executed periodically at each of a plurality of periods; 
 execute the first task thread during a first period of the plurality of periods; 
 determine a second core in which the first task thread is to be executed during a second period of the plurality of periods; 
 instruct the second core to enter a waiting period prior to transferring the first task thread thereto, wherein entering the waiting period includes spinning or a combination of spinning and sleeping by the second core until the second period occurs; 
 transfer the first task thread to the second core while the second core is in the waiting period; and 
 
 the second core configured to:
 stop execution, by the second core, of a second task thread executing on the second core in response to the first core instructing the second core to enter the waiting period and subsequently entering the waiting period; 
 execute the first task thread when the second period occurs after the first task thread is transferred thereto. 
 
 
     
     
       7. The apparatus according to  claim 6 , wherein the first core executes another thread if the task thread is transferred to the second core. 
     
     
       8. The apparatus according to  claim 6 , wherein the second core executes the task thread and determines a third core in which the task thread is to be executed during a third period according to the task thread arrangement scheme. 
     
     
       9. The apparatus of  claim 6 , wherein the first core is configured to,
 first transfer codes and read only data associated with the task thread from the first core to the second core during execution thereof by the first core, and 
 second transfer read-write data associated with the task thread from the first core to the second core after execution thereof by the first core is complete.